When to test after exposure
A window period is the gap between exposure and the point a test can detect an infection. Testing inside it can produce a negative result even when an infection was transmitted.
Diagnik Health Library · Updated
First 72 hours
If you may have been exposed to HIV in the last 72 hours, contact a clinician, urgent care or an emergency department about post-exposure prophylaxis. It is time-critical, and a self-test cannot substitute for it.
Roughly how long to wait
- Chlamydia, gonorrhea, trichomoniasis: detectable within days to about two weeks.
- Syphilis antibodies: usually a few weeks; very early tests can be negative.
- HIV antibodies: guidance describes a window of up to about three months.
Testing twice is normal
Many people test early for reassurance and again after the window period for certainty. That is a reasonable plan — as long as the early result is treated as provisional rather than final.
Tests mentioned in this guide
OraQuick In-Home HIV Test
An HIV answer at home, in 20 to 40 minutes, with no blood.
First To Know Syphilis Test Kit
A single drop of blood, a syphilis answer in 15 minutes.
Visby Women's Sexual Health Test
Three common infections from one self-collected swab, in about 30 minutes.
Frequently asked questions
- How long should I wait to test for HIV after exposure?
- Antibody tests have a window of up to about three months. Testing sooner is possible, but a non-reactive result should be repeated after the window has passed.
- Can I test the next day?
- You can, but a negative result the next day says very little about that exposure. Timing is what gives a result meaning.
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Sources
Educational information only, not a medical diagnosis or treatment advice. Screening results always need confirmation by a clinician.
This guide is general health information about screening tests. It is not a diagnosis and does not replace care from a clinician. See our medical disclaimer.